Abstract: MicroRNAs are the endogenous non-coding RNAs that regulate gene expression by mediating gene post-transcriptional silence. Among them, miR-21, miR-17-92, miR-214, miR-26a, miR-221, miR-222 and so on mainly suppress the expression of PTEN phosphohydrolase through targeting PTEN mRNA 3’-UTR. PTEN plays an important role in cell proliferation, apoptosis, migration and invasion, and its low expression will induce tumorigenesis.